I've had my eye on that game. Unlike Minecraft, Cubeworld has all the endless, pixelated RPG adventure I could want ... yet little of the creative world building that Minecraft offers. RPG adventure, or world building? I could just play Terraria, but it being 2D is a big turnoff. I haven't played Cubeworld or Terraria yet (and Cubeworld is, as you said, still in alpha), so I can't make any definitive arguments.
To those who have tried these games (or other similar games), which do you prefer?
I gotta say, I do like the character creator of Cubeworld (much like 3D Dot Game Heroes). You made Schala! And I've seen that a sword-wielding frog is one of the default races...